Universal radio frequency shield removal

ABSTRACT

Apparatus and methods for removing components soldered to a printed circuit board (PCB). Embodiments presented generally include a contact plate having a component specific platform offset from the contact plate body. The offset platform may be substantially identical in size and shape as the component to be removed. Accordingly, contact between a heated platform and component may allow for conductive heating to occur based on contact with the component. Thus, forced air or convective heating of the component does not occur such that solder joint defects in adjacent components may be prevented. A vacuum retention port may be provided at an interface of the platform and component when in contact. The vacuum retention port may allow the freed component to be removed from the PCB using vacuum to hold the freed component to the platform. Also, apparatus for automation of a process according to the forgoing are presented.

BACKGROUND

When assembling electronic devices, it is common to solder components toa printed circuit board (PCB) to attach components to the PCB. Thesoldering of components not only attaches the components to the PCB butmay also be used to establish an electrical connection between the PCBand an electronic component. In this regard, both electrically coupledas well as non-electrically coupled components may be soldered to thePCB in order to maintain a position on the PCB.

Often components to be affixed to a PCB are positioned adjacent to thePCB with solder being positioned between the component and PCB. Theassembly may then be heated such that the solder melts. When cooled, thesolder may in turn solidify and attach the component to the PCB. Thisprocess of melting solder to affix a component to a PCB is commonlyreferred to as reflow.

During the assembly process of electronic devices, various tests may beconducted to determine whether the components that have been attached tothe PCB are operative and properly attached. Examples of processes thatmay be conducted on a PCB to determine correct placement, attachment,and operation of components include function node testing and x-rayinspection. Based on the results of these tests, it may be necessary toremove components from the PCB due to a faulty attachment or otherdetected process defects. The removal of components may be necessary inorder to replace a malfunctioning component, reattach a component, oraccess other components on the PCB. This process may be commonlyreferred to as rework.

For example, many PCBs include electro-magnetic (e.g., radio-frequency(RF)) shields that cover other components attached to the PCBs.Particularly in the field of electrical communication devices, RFshields may be employed to protect sensitive components frominterference from RF energy. In this respect, many sensitive componentsmay be located below an RF shield that is in turn attached to a PCB.Therefore, if one of the components contained under the RF shield needsto be removed or the RF shield itself needs replaced, the RF shield mayneed to be removed.

Existing methods for removal of RF shields often involve heating the RFshield with forced hot air to melt the solder attachment of the RFshield to the PCB. However, due to the difficulty in controlling aforced hot air process, directing the flow of hot air, the forced hotair heating of the RF shield may also create problems with othercomponents and their solder joints. For example, the direction of theforced hot air may be difficult to control. As such, the forced hot airmay be directed to portions of the PCB that are not to be reworked.Furthermore, the amount of heat transferred to the PCB is difficult tocontrol in a forced hot air process. The temperature of the air existingthe forced hot air source may be difficult to regulate and the amount ofheat transferred may depend on many variables such as the temperature ofthe air existing the source, the distance of the source from thecomponent, the flow rate of air existing the source, and other factorsthat may be variable and be difficult to control. The use of forced hotair may cause unintended reflow of adjacent components and may lead tosolder joint defects in these adjacent components. These defects mayoccur to components adjacent to the RF shield that are not to be removedfrom the PCB. Examples include causing unintended reflow, delamination,plate lifting, wetting problems, dewetting problems, and other potentialdefects in components adjacent to the RF shield that has been heatedwith forced hot air. These defects may occur for components adjacent tothe RF shield or components contained underneath the RF shield.

In addition to the potential for solder joint defects when using forcedhot air to remove an RF shield, the process may be tedious and require arelatively long cycle time to remove the RF shield. The processgenerally involves an operator manipulating a forced hot air gun inorder to heat the RF shield. The operator may be required to take greatcare to diminish the potential for solder joint defects in adjacentcomponents. As such, the cycle time may be relatively long for each RFshield that needs to be removed. For instance, the cycle time forremoving an RF shield with forced hot air heating may take between sixto eight minutes and may require highly trained, certificated operatorsto operate the machine to reduce the potential for solder joint defects.Additionally, the equipment costs for the equipment necessary to performforced hot air RF shield removal may be high.

Further still, once the RF shield has been heated by forced hot airheating, it is still necessary to remove the RF shield from the PCB.Existing methods for removal of an RF shield once heated by forced hotair heating include vacuum pick up and removing the RF shield manuallyby grasping (e.g., with tweezers). In this regard, the removal the RFshield once heated may be tedious and require high skill in order toprevent damage to the remainder the PCB when removing the RF shield withtweezers as adjacent components may also be heated such that they aresusceptible to being damaged when manipulating portions of the PCB withtweezers.

SUMMARY

A first aspect of the present invention includes an apparatus forremoving a component attached to a printed circuit board (PCB) from thePCB. The apparatus includes a heating element, a contact plate inthermal communication with the heating element, and a vacuum retentionport extending through the contact plate and operative to selectivelycommunicate with a vacuum source. The contact plate is contactable withthe component such that when the contact plate is in contact with thecomponent the heating element heats the component and the vacuumretention port is covered by the component.

A number of feature refinements and additional features are applicableto the first aspect. These feature refinements and additional featuresmay be used individually or in any combination. As such, each of thefollowing features that will be discussed may be, but are not requiredto be, used with any other feature or combination of features of thefirst aspect.

For instance, the component may be an electro-magnetic shield operativeto protect components on the PCB from electro-magnetic interference. Inone embodiment, the component may be a radio-frequency (RF) shieldoperative to protect components on the PCB from radio-frequency (RF)interference.

In another embodiment, the heating element may include a vacuum port incommunication with the vacuum retention port. The contact plate may beremovably attachable to the heating element and may include a platformextending from the contact plate. The platform may have a substantiallyidentical profile as the component. In this regard, only the platformmay contact the component when the contact plate is in contact with thecomponent. The vacuum retention port may terminate at an interfacebetween the platform and the component when the contact plate is incontact with the component.

In one embodiment, the contact plate may be chosen from among aplurality of contact plates and the plurality of contact plates mayinclude different platforms having different profiles for differentcomponents to be removed from the PCB. The contact plate may be clampedto the heating element using at least one clamping mechanism.

The apparatus may also include a temperature controller operative tocontrol the heating element to maintain a predetermined temperature ofthe contact plate. Additionally, the apparatus may include a vacuumcontroller operative to control a vacuum at the vacuum retention port toselectively establish a vacuum at the vacuum retention port. In anotherembodiment, the apparatus includes a PCB holder operative to hold thePCB stationary when the contact plate is in contact with the component.

A second aspect of the present invention includes an automated systemfor removing a component attached to a printed circuit board (PCB) fromthe PCB. The system includes a heating element, a contact plateremovably attached to the heating element and in thermal communicationwith the heating element, and a vacuum retention port extending throughthe contact plate and in selective communication with a vacuum sourcesuch that a vacuum is selectively established at the vacuum retentionport. Furthermore, the system includes an actuator engaged with theheating element and operative to move the contact plate with respect tothe PCB between a non-contacting position and a contacting position.When in the contacting position the contact plate contacts the componentand the vacuum retention port is located at an interface between thecontact plate and the component and the component covers the vacuumretention port. The system also includes a PCB holder operative toretain the PCB. When in the contacting position the contact plate heatsthe component and the vacuum is maintained at the vacuum retention port,such that when the contact plate is moved to the non-contacting positionthe component is held against the contact plate by the vacuum andremoved from the PCB.

A number of feature refinements and additional features are applicableto the second aspect. These feature refinements and additional featuresmay be used individually or in any combination. As such, each of thefollowing features that will be discussed may be, but are not requiredto be, used with any other feature or combination of features of thesecond aspect.

In one embodiment, the system may also include a controller operative tocontrol the heating element to maintain a predetermined temperature atthe contact plate, control the vacuum source such that vacuum may beselectively established at the vacuum retention port, and control theactuator to position the contact plate between the non-contactingposition and the contacting position. Additionally, the system mayinclude a slide to which the PCB holder is attached. The slide may beoperative to move with respect to the contact plate from a loadingposition to a work position. When in the loading position, the PCBholder may be accessible by an operator such that a PCB may be loadedonto the PCB holder. When in the work position, the PCB may be alignedwith the contact plate such that actuation of the actuator results inplacement of the contact plate in the contacting position.

In one embodiment, the controller may be operative to control theactuator, in response to movement of the slide to the work position, toposition the contact plate from the non-contacting position to thecontacting position, maintain the contact plate in the contactingposition for a predetermined amount of time, and after the predeterminedamount of time, move the contacting plate to the non-contacting positionwhile controlling the vacuum source to establish a vacuum at the vacuumretention port.

Additionally, the system may include a component disposal draweroperative to move with respect to the contact plate from a closedposition to an open position. When the component disposal drawer is inthe open position, upon termination of the vacuum at the vacuumretention port, the component may separate from the contact plate andmay be disposed within the component disposal drawer.

A third aspect of the present invention includes a method for removing acomponent attached to a PCB from the PCB. The method involves contactingthe component with a contact plate in thermal communication with aheating element such that a vacuum retention port extending through thecontact plate is covered by the component, melting solder attaching thecomponent to the PCB in response to the contacting, creating a vacuum atthe vacuum retention port such that the component is held against thecontact plate by the vacuum, and moving the contact plate with respectto the PCB during the creating such that the component is retained onthe contact plate and removed from the PCB.

A number of feature refinements and additional features are applicableto the third aspect. These feature refinements and additional featuresmay be used individually or in any combination. As such, each of thefollowing features that will be discussed may be, but are not requiredto be, used with any other feature or combination of features of thethird aspect.

In one embodiment, the component may be an electro-magnetic shied. Forexample, the electro-magnetic shield may be a radio-frequency (RF)shield.

In another embodiment, the contact plate may be a customized removableplate having a platform corresponding to a profile of the component.Only the platform may contact the component when the contact plate is incontact with the component. The method may further include selecting acontact plate from a plurality of different contact plates.Additionally, the method may involve removably attaching the contactplate to the heating element. The removably attaching may includesclamping the contact plate to the heating element using a quick releasemechanism.

A fourth aspect of the present invention includes an apparatus forremoving a component attached to a printed circuit board (PCB) from thePCB. The apparatus includes a heating element and a contact plate inthermal communication with the heating element. The contact plate isoperative to contact only the component such that the contact platecontacts substantially all of an exposed area of the component such thatheat is conducted directly from the contact plate to the component.

A number of feature refinements and additional features are applicableto the fourth aspect. These feature refinements and additional featuresmay be used individually or in any combination. As such, each of thefollowing features that will be discussed may be, but are not requiredto be, used with any other feature or combination of features of thefourth aspect.

For instance, in one embodiment, the contact plate may include aplatform extending from the contact plate that has a substantiallyidentical profile as the component. Additionally, the platform mayinclude a vacuum retention port extending through the contact plate. Thevacuum retention port may be operative to selectively communicate with avacuum source such that the vacuum retention port is covered by thecomponent when the platform contacts the component.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a heating element assembly.

FIG. 2 is an exploded perspective view of a heating element assembly andcontact plate assembly.

FIG. 3 is an alternative embodiment of a heating element assembly.

FIGS. 4A-B include a front side view and back side view of a contactplate.

FIG. 5 is a cutaway perspective view of a heating element and contactplate assembly in an assembled state.

FIGS. 6A-B are cross-sectional views of a heating element assembly andattached contact plate assembly and a PCB from which a component is tobe removed.

FIG. 7A-B are perspective views of one embodiment of an apparatus forremoval of a component from a PCB.

FIG. 8 is a perspective view of another embodiment of a system forremoval of a component from a PCB.

FIG. 9 is a front elevation view of the system shown in FIG. 8.

FIGS. 10A-B are section views taken along section line 10 in FIG. 9showing a PCB holder in a work position and loading position,respectively.

FIG. 11 is a perspective view of a PCB holder that may be used in thesystem depicted in FIG. 8.

DETAILED DESCRIPTION

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and are herein described in detail. It shouldbe understood, however, that it is not intended to limit the inventionto the particular form disclosed, but rather, the invention is to coverall modifications, equivalents, and alternatives falling within thescope and spirit of the invention as defined by the claims.

The embodiments described herein generally include apparatus and methodsthat may be utilized to remove a component from a PCB. The component tobe removed may be any component attached to the PCB by way of a solderconnection. Examples include integrated circuit devices and the like. Inone embodiment, the component to be removed is an electro-magneticshield used to protect components on the PCB from electro-magneticenergy. For instance, the component may be a radio-frequency (RF) shieldthat may or may not be covering additional components.

The component to be removed may be affixed to the PCB by way of a solderconnection such that upon melting of the solder comprising the solderconnection, the component may be removed from the PCB without damagingthe component or the PCB. To accomplish melting of the solder formingthe solder connection between a component and a PCB, embodimentsdisclosed herein may include a contact plate having a platform that maybe of the same profile as the component to be removed. In this regard,the contact plate may be brought into contact with the component suchthat only the component is contacted by the platform of the contactplate. As the platform of the contact plate may be of the same profileas the component, the component to be removed may be the only portion ofthe PCB contacted by the contact plate. That is, the component, whenattached to the PCB may have an exposed area that is contacted by thecontact plate. The exposed area of the component may correspond to thecomponent's footprint or profile on the PCB. The contact plate may beadapted to contact substantially all of the component's exposed areawithout contacting any other component of the PCB or the PCB itself. Inthis regard, heat may be transferred directly to the component byconductive heat transfer at the point of contact. This may prevent oralleviate the problem of heat being transferred into other componentswhich are not to be removed from the PCB. Thus, the embodimentspresented herein may facilitate prevention of solder joint defects inadjacent components to the component that is to be removed.

In addition to providing a contact plate having a platform matching theprofile of a component to be removed, embodiments presented below mayinclude a vacuum retention port that terminates at an interface betweena platform and a component when in contact with each other. The vacuumretention port may allow for a component freed from the PCB (i.e., afterhaving the solder connection melted) to be retained on the platformwhich is in contact with the component. Thus, the contact plate may bemoved with respect to the PCB such that the component remains heldagainst the platform such that as the contact plate is moved away fromthe PCB the component remains held against the platform. That is, thefreed component may be retained on the platform and effectively removedfrom the PCB.

With respect to FIGS. 1 and 2, a heating element assembly 100 and acontact plate assembly 200 are shown. The heating element assembly 100may generally include a heating element body 110. At least one heatingelement 112 may be disposed within the heating element body 110. In theembodiment depicted in FIG. 1, two heating elements 112 are disposedwithin the heating element body 110. The heating element body 110 mayconduct heat throughout the heating element body 110 such thatsubstantially the entire body of the heating element body 110 is heatedto approximately the same temperature. The heating elements may be anytype of heating element known in the art (e.g., any type of electricalheating element). In one embodiment, the heating elements 112 may beresistive electric heaters. The heating elements may be controlled by atemperature controller such that a predefined temperature of the heatingelement body is maintained. The control of the temperature may beautomated or rely on manual control by an operator.

The heating element body 110 also may include structures or featuresthat allow a contact plate 210 of the contact plate assembly 210 to beattached to the heating element. These structures and features mayinclude fasteners, sliding connections, clamping connections,interference connections, or other known means of attachment. Asexplained below it may be advantageous to allow for removal of thecontact plate 210 from the heating element body 110. In one embodiment,the heating element body 110 includes attachment holes 114 that may beused to attach the contact plate 210 as will be described below.

The heating element body 110 may also include a vacuum port 120 that mayextend through the heating element body 110. The vacuum port 120 mayterminates at a face 122 of the heating element body 110. The face 122of the heating element body may be adjacent to the contact plate 210such that when the contact plate 210 is attached to the heating elementbody 110, the contact plate 210 may contact the face 122. In thisregard, the vacuum port 120 may terminate at an interface between theheating element body 110 and the contact plate 210 when attached. Theface 122 of the heating element body 110 & face 250 of the contact plate210 may be flush with one another when in contact. As such, either orboth of the faces 122 or 250 may include an appropriate surface finishor texture to avoid vacuum loss when a vacuum is introduced as will befurther discussed below.

The heating element body 110 may further include insulators 116. In oneembodiment, the insulators 116 may be ceramic insulators. In thisregard, the heating element body 110 may be attached to a housing bodyor other support without transferring a substantial amount of heat toother parts of a device incorporating the heating element body 110. Inother words, insulating material may be provided on the heating elementbody 110 to thermally isolate the heating element body 110 from otherportions of a device.

The contact plate 210 may include attachment features corresponding tothe attachment features of the heating element body 110. In theembodiment depicted in FIG. 2, the contact plate 210 may include throughholes 214 that may correspond to and be aligned with the attachmentholes 114 provided in the heating element body 110. The contact plateassembly 200 may also include fasteners 212 that extend through thethrough holes 214 and engage the attachment holes 114. For instance, thefasteners 212 may include bolts that extend through the through holes214 and thread into threaded attachment holes 114. In this regard, thecontact plate 210 may be affixed to the heating element body 110. Theheating element body 110 may include guide pins 132 that may be disposedin alignment hoes 130 that correspond with alignment holes located onthe contact plate 210 to assist in alignment of the contact plate 210with the heating element body 110 to facilitate prevention ofmisalignments or inverted plates.

In an alternative embodiment depicted in FIG. 3, one or more clampingmechanisms 300 may be attached to a heating element body 110. In thisembodiment, the clamping mechanisms 300 may be operative to clamp thecontact plate 210 to the heating element body 110. In this regard, theattachment and detachment of the contact plate 210 to the heatingelement body 210 may be simplified such that contact plate changes mayoccur more quickly and be easier for an operator to accomplish. Theclamping mechanism 300 may be attached to the heating element body 110by attachment bolts 310. A clamp end 302 may be provided at the end of aclamping rod 304. The clamping rod 304 may be affixed at the other endto a cam 308 that may be actuated with a lever arm. Upon actuation ofthe cam 308 with the lever arm, the clamping rod 304, along with theclamp end 302 may be drawn toward the heating element body 110 such thatthe contact plate 210 disposed between the clamp end 302 and the heatingelement body 110 may be held in place against the heating element body110. An adjustment nut 312 may be provided at an end of the clamping rod304 to adjust the location of the clamp end 302 to produce differentamounts of clamping force on the contact plate 210.

When the heating element body 110 and the contact plate 210 have beenattached, the vacuum port 120 defined in the heating element body 110may be brought into communication with a vacuum retention port 220 thatextends through the contact plate 210. As such, a vacuum exposed to thevacuum port 120 in the heating element body 110 may in turn becommunicated to the vacuum retention port 220 as will be describedfurther below.

In any regard, the contact plate 210 may be attached to the heatingelement body 110 such that the contact plate 210 is also heated by theheating element 112. The contact plate 210 may also include a platform222 defined by platform sidewalls 224 that extend away from the contactplate 210 in a direction opposite from the heating element body 110. Inthis regard, the platform 222 may extend from the contact plate 210 suchthat the platform 222 is offset from the remainder of the contact plateIn one embodiment, the offset of the platform 222 may be proportional tothe highest component on the board that is to be reworked. In thisregard, when the platform 222 contacts the component, the remainder ofthe contact plate 210 may be free from contact with the remainder (e.g.,the highest component) of the PCB. The platform 222 may have a profilethat corresponds to a component which is to be removed from the PCB.That is, the platform 222 may have a substantially identical outline orshape as a component which is to be removed such that when the contactplate 210 is brought in to contact with a component, the platform 222may be the only portion of the contact plate 210 touching the componentor any other portion of the PCB. As such, heat may be transferred byconducting heat directly to the component. As such, heat transferredinto the component may be transferred directly to the component withouta substantial amount of heat being directed to other components on thePCB adjacent to the component to be removed.

Furthermore, when the platform 222 is in contact with a component, avacuum retention port 220 may be covered by the component. Accordingly,a vacuum produced at the vacuum retention port 220 while the platform222 is in contact with a component may allow the component to be heldagainst the platform 222. That is, the contact between the platform 222and component may form a seal that allows a vacuum to act on thecomponent at the vacuum retention port 220 to retain the componentthereon by virtue of the vacuum holding the component to the platform222.

Front and rear perspective views of the contact plate 210 are shown inFIGS. 4A and 4B respectively. In these front and rear perspective views,the vacuum retention port 220 as well as a channel 226 can be seen. Thefront view of the contact plate 210 in FIG. 4A includes a termination ofthe vacuum retention port 220 on the platform 222. The contact plate 210may also include a channel 226 defined in the contact plate 210 forvacuum distribution. In this regard, the channel 226 may extend betweenthe vacuum port 120 of the heating body 110 and the vacuum retentionport 220 when the contact plate 210 is attached to the heating elementbody 110.

It may be advantageous to facilitate removal of components attached to aPCB that are at different locations on the PCB. Thus, contact platebodies having platforms of different profiles at different locations maybe selectively attached to the heating element body 110 based on thecomponent to be removed. In this regard, the vacuum port 120 may belocated on the heating element body 110 at a central location on theheating body 110. The channel 226 may be defined in the contact plate210 in order to provide a passage between the vacuum port 120 on theheating element body 110 to a vacuum retention port 220 that is offsetfrom the vacuum port 120. As removal of components at differentlocations and of different sizes on the PCB may be facilitated,different contact plates may be provided such that the platform 222 andvacuum retention port 220 may be at different relative locations on thecontact plate 210 and the heating element body, respectively. Thedifferent platforms may also have different profiles for differentcomponents to be removed. The vacuum retention port 220 may be offsetfrom the vacuum port 120, such that the channel 226 defined by thecontact plate 210 may be provided in the contact plate 210 to link thevacuum retention port 220 and the vacuum port 120. In this regard, thechannel 226 may provide for communication between the vacuum retentionport 220 and the vacuum port 120.

As further shown in the cutaway perspective view in FIG. 5, the channel226 may be defined in the contact plate 210 between the vacuum port 120and the vacuum retention port 220. When the contact plate 210 isattached to the heating element body 110, the channel 226 may be sealedsuch that there is little or no vacuum loss at the interface of thecontact plate 210 and the heating element body 110. Furthermore, theheating element body 110 may include a vacuum inlet 124 extendingthrough the heating element body 110 that may provide communicationbetween the vacuum port 120 and a vacuum source. In this regard, avacuum applied at the vacuum inlet 124 may result in a vacuum beingapplied throughout the vacuum port 120, the channel 226 and the vacuumretention port 220 (collectively the vacuum path).

FIG. 6A shows an end view of a PCB assembly 600 in contact with acontact plate 240. While the PCB assembly 600 is depicted as only havingone component 620, it will be understood that the PCB assembly 600 mayfurther have additional components adjacent to or under the component620. FIG. 6B is a cross section view taken along section line B-B inFIG. 6A. FIG. 6C shows the cross section of FIG. 6B once a component hasbeen removed from the PCB 610. The contact plate 240 may have adifferent profile platform 222 provided at a different location suchthat a different length and/or shaped channel 226 may be provided basedon a component 620 to be removed.

As may be appreciated in FIG. 6B, the profile of the platform 242 may besimilar to that of the component 620 such that when the contact plate240 contacts the component 620 only the raised platform 242 contacts thecomponent 620. In this regard, upon activation of the heating element112, heat may be conducted through the heating element body 110 as wellas the contact plate 240. As such, the platform 242 in contact with thecomponent 620 may result in heat being transferred directly byconduction to the component 620. As such, a solder connection 612attaching the component 620 to the PCB 610 may also be heated such thatthe solder may be melted and the component 620 may be freed from thePCB.

Also, while the platform 242 is still in contact with the component 620,and the melting point of the solder forming the attachment to thecomponent has been reached, a vacuum may be introduced at the vacuuminlet 124. In this regard, the vacuum may be communicated to the vacuumpath. As the vacuum retention port 220 may terminate adjacent to thecomponent 620, a vacuum at the vacuum retention port 220 may result inthe component 620 being held against the platform 242.222. The forceacting on the component 620 urging it against the platform 242 may besufficient to overcome the surface tension from liquid solder. As such,the component 620 may be removed from the PCB 610.

In this regard, and as shown in FIG. 6C, the PCB 610 and the contactplate 240 and be moved with respect to one another. In that the solderconnection 612 between a component 620 and the PCB 610 may have beenmelted as a result of heat application to the component 620, relativemovement between the PCB 610 and the contact plate assembly 200 mayresult in the component 620 being removed from the PCB 610. This may befacilitated because a vacuum at the vacuum retention port 220 may holdthe component 620 to the platform 242 by way of the vacuum acting on thecomponent 620.

It will be understood that the PCB 610 may be moved away from thecontact plate 240, the contact plate 240 may be moved away from the PCB610, or both. In any regard, relative movement of the contact plate 240and PCB 610 with vacuum pressure applied at the vacuum attention port222 and the solder connection 612 being melted by action of the heatingelement 112 may result in the component 620 being removed from the PCB610. Thus a PCB assembly 600′ may result, wherein the component has beenremoved from the PCB, yet all other components remain without havingbeen contacted by the contact plate 240.

As shown in FIGS. 7A-B, a heating element assembly 100 and the contactplate assembly 200 may be incorporated into a device 700 for removal ofa component from a PCB. Generally, a PCB 730 having a component to beremoved attached thereto may be placed on the device 700 such that thecomponent be removed is in contact with the contact plate 210 andspecifically, the component may be in contact with the platform 222 ofthe contact plate 210 as described with reference to FIGS. 6A-B. Theapparatus 700 may include a temperature control module 710 that isoperative to control the heating elements 112 disposed in the heatingelement body 110. In this regard, a predetermined temperature may beestablished at the heating element body 110 such that the heatingelement body 110 and the contact plate 210 are maintained at thepredetermined temperature. Alternatively, the heating elements 112 maybe activated once the PCB is in contact with the contact plate assembly210, however doing so may adversely impact cycle time.

Moreover, vacuum piping 722 may be provided between a vacuum source 720and the heating element body 110. The vacuum piping 722 may be operativeto link a vacuum inlet 124 (as shown in FIG. 5) of the heating elementbody 110 to a vacuum source 720. As such, the vacuum source 720 may becontrolled to selectively create a vacuum at the vacuum inlet 124. Thevacuum source 720 may be controlled in any way that selectivelyestablishes a vacuum at the vacuum retention port 220 of the contactplate 210. For example, a control (e.g., a valve) may be provided in thevacuum piping 722 or elsewhere in the vacuum path, or an externalcontrol may be provided that allows for control over the creation of avacuum at the vacuum inlet 124. In any regard, a vacuum is selectivelyestablished at the vacuum retention port such that a component may beheld against a platform 222 of the contact plate 210.

In this instance, insulation may be provided such that the heatingelement body 110 does not transfer a substantial amount of heat to thedevice chassis to prevent damaging the chassis. Also, PCB supports 230may be provided on the contact plate 210 to support the PCB 730 when incontact with the contact plate 210. The PCB supports 230 may also beinsulating such that the supports do not transfer heat from the contactplate 210 to the PCB 730.

When operating the device 700, an operator may position a PCB 730 withthe component to be removed facing the contact plate 210. The PCB 730may rest on the PCB supports 230 such that the component to be removedis aligned with and contacts the platform 222 of the contact plate 210.The heating element body 110 may be at a predetermined temperature asregulated by the heating elements 112 such that the contact plate 210and the platform 222 are at the predetermined temperature. Uponcontacting the component to the platform 222, heat may be transferred tothe component by conductive heating. This may result in a solderattachment holding the component to the PCB to undergo a phase changeand melt. In this regard, the component may be freed from the PCB 730.

After a predetermined amount of time (e.g., enough time to ensure thesolder attaching the component has melted but not enough time totransfer a significant amount of heat to the remainder of the PCB so asto prevent solder joint defects in adjacent components), a vacuum source720 may be controlled such that a vacuum is introduced in the vacuumpiping 722. In this regard, low-pressure may be developed in the vacuumpiping 722, the vacuum port 120, channel 226, and the vacuum retentionport to 220. In that the component may be in contact with the platform222 and may cover the vacuum retention port 220, vacuum introduced atthe vacuum retention port 220 may result in the component forming a sealwith the platform 222 and the component may be held against the platform222 by way of the vacuum acting on the component at the vacuum retentionport 220. The PCB 730 may be lifted from the apparatus 700. Because thecomponent may be free from the PCB 730 by virtue of the melting of theattachment solder, the component may remain in place against theplatform 222 due to the vacuum interaction at the interface of thecomponent and the platform 222 when the PCB 730 is lifted from thedevice 700. Thus, the component may be removed from the PCB 730. Thevacuum source 720 may be controlled such that the vacuum present at thevacuum retention port 220 may be terminated and the component may bereleased.

FIG. 8 shows an alternative embodiment of a system 800 for removing acomponent from a PCB. The system 800 generally operates in the samemanner to free a component and retain the component. That is, the system800 may include a heating element assembly 100 and contact plateassembly 200 similar to those described above. Additionally, the system800 may include an actuator 870 to which the heating element assembly100 is attached. The system 800 may also include a PCB holder 820mounted to a sliding platform 830. The system 800 may have a temperaturecontroller 840 as well as a timer 810 to facilitate control over thesystem 800. A utility compartment 850 may be provided to housecomponents of the system 800 that do not need to be regularly accessedby an operator. Examples of components house din the utility compartment850 may include a controller (e.g., a PLC logic controller), a vacuumsource or vacuum controller, power supplies, and other equipment such aspneumatic valves and the like.

The actuator 870 to which the heating assembly 100 may be attached maybe operative to move the heating element assembly 100 and contact plateassembly 200 with respect to a PCB holder 820. The actuator 870 may be apneumatic actuator capable of producing linear motion with respect tothe PCB holder 820. In this regard, the actuator 870 may be used to movethe contact plate assembly 200 and heating element assembly 100 withrespect to a PCB held in the PCB holder 820 such that the contact plateassembly 200 contacts the component to be removed from the PCB similarto the arrangement shown in FIG. 6A. The actuator 870 may also be movedwith respect to the PCB holder 820 such that the contact plate assembly100 is moved away from a PCB held by the PCB holder 820. In this regard,similar to the embodiments discussed above, a vacuum may be establishedat a vacuum retention port on the contact plate assembly 200. This mayallow the component to be held against a platform of the contact plate.Upon freeing (e.g., melting of the solder) of the component, movement ofthe actuator 870 away from the PCB while the component is held againstthe platform using a vacuum may allow the component to be removed fromthe PCB.

FIG. 9 is a front elevation view of the system 800. FIG. 10A-B aresection views taken along section line 10 in FIG. 9. FIG. 10A shows aPCB holder 820 in a work position and FIG. 10B shows a PCB holder 820 ina loading position. The actuator 870 may include insulating material 872between the actuator 870 and the heating element assembly 100. Theactuator 870 may be disposed above a PCB holder 820 when the PCB holder820 is in a work position as shown in FIG. 10A. The PCB holder 820 maybe moved between a work position shown in FIG. 11 and a loadingposition, wherein the sliding platform 830 is moved transversely to thedirection of motion of the actuator 870 such that a user may access thePCB holder 820. The PCB may be placed on and held in place by the PCBholder 820 as will be described below. The PCB holder 820 may be movedfrom the loading position to the work position shown in FIG. 10A suchthat the PCB holder 820 is disposed below the actuator 870.

In operation, the PCB holder 820 may be moved on slide 832 such that thePCB holder 820 is disposed in the loading position as shown in FIG. 10Band may be more easily accessed by an operator. The operator may load aPCB into the PCB holder 820. The PCB holder 820 may be moved to theworking position shown in FIG. 10A. The return of the PCB holder 820 tothe position shown in FIG. 10A may trigger the actuator 870 to belowered toward the PCB holder 820. The lowering of the actuator 870 maybring the contact plate assembly 200 into contact with the PCB asdescribed above with regard to FIG. 6A. The timing controller maymaintain the contact plate assembly 200 in contact with the PCB for apredetermined amount of time such that a soldered connection of acomponent may be melted. A vacuum source may be activated such thatvacuum is introduced to a vacuum retention port such that the detachedcomponent is held in place against the contact plate assembly 200. Theactuator 870 may be moved away from the PCB holder 820 such that the PCBis held in place by the PCB holder and the component travels with thecontact plate assembly 200. Thus, the component may be removed from thePCB.

Once the actuator 870 has moved away from the PCB holder 820, acomponent disposal drawer 860 may be moved from a retracted position asshown in FIG. 10A by a pneumatic cylinder 864 such that the componentdisposal drawer 860 may be placed generally below the contact plateassembly 200. The vacuum holding the component to the contact plateassembly 200 may be released and the component may be allowed to fallinto the component disposal drawer 860. The component disposal drawer860 may be retracted back to the position shown in FIG. 10A. Thus, thecomponent may be removed from the contact plate assembly 200 and theprocess may resume with another PCB to which a component is attachedbeing loaded into the PCB holder 820.

FIG. 11 is a perspective view of the PCB holder 820 that may be mountedto the sliding platform 830. The PCB holder 820 may include a firstplatform 1102 and a second platform 1104. The first platform 1102 may beaffixed to the slide platform 830 by way of fasteners 1112 passingthrough slots 1113. The slots 1113 may allow for movement of the firstplatform 1102 with respect to the slide platform 830. That is, thefasteners 1112 may be loosened and thumbwheels 1106 be threaded into orout of blocks 1108 such that the first platform 1102 slides in adirection corresponding to the length of the slot 1113.

Additionally, the second platform 1104 may also be attached to the firstplatform 1102 by way of fasteners 1110. The fasteners 1110 may passthrough slots 1111. When fasteners 1110 are loosened, thumbwheels 1107may be threaded into or out of blocks 1109 to produce lateral movementof the second platform 1104 in a direction along the length of slots1111 and generally orthogonally to that of the first platform 1102.

The PCB holder 820 may also include PCB retention arms 1122. The PCBretention arms 1122 may include a resilient member that provides abiasing force that urges a PCB against the PCB holder 820. The PCBretention arms 1122 may be attached to posts 1120 that space the PCBretention arms 1122 from the second platform 1104. In this regard, a PCBmay be placed on the second platform 1104 and PCB retention arms 1122may be moved with respect to the PCB to urge the PCB against the secondplatform 1104. As such, the PCB may be held in place on the PCB holder820. The adjustment of the first platform 1102 and second platform 1104may allow for adjustment such that the PCB may be positioned withrespect to the contact plate assembly 200 when lowered by the actuator870. In this regard, the PCB may be positioned such that only thecomponent to be removed is contacted by the platform 222 having aprofile substantially similar to the competent to be removed.

The embodiments presented herein may be advantageous over prior systemsin that the embodiments presented herein may facilitate reduction orprevention of solder joint connections and other defects that PCBs aresusceptible to sustaining when removing components for rework. As thecomponent to be removed is heated by way of direct conductive heating,excess heat is less likely to affect adjacent components that do notneed to be removed. Unlike forced hot air heating, the control of heattransfer to the component facilitates heating of the component withoutsubjecting adjacent components to heat that may lead to solder jointdefects and other issues with excess heat. As such, the component may beremoved without the intervention of highly skilled workers utilizingexpensive machines. Furthermore, the embodiments presented herein allowfor removal of a component while heating without the need for anoperator to physically manipulate the component to be removed withtweezers or other implements. Rather, a vacuum is used to remove thecomponent, thus lessening the risk that the component or adjacentcomponents are subjected to damage.

Further still, the embodiments presented herein may provide forautomation of the rework process such that the cost associated with therework process may be reduced. As stated above, the embodimentspresented may facilitate rework by operators without highly developedskill sets. Furthermore, the cycle time associated with componentremoval may be significantly reduced from a system using forced hot airand tweezers to remove a component.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and description isto be considered as exemplary and not restrictive in character. Forexample, certain embodiments described hereinabove may be combinablewith other described embodiments and/or arranged in other ways (e.g.,process elements may be performed in other sequences). Accordingly, itshould be understood that only the preferred embodiment and variantsthereof have been shown and described and that all changes andmodifications that come within the spirit of the invention are desiredto be protected.

1.-16. (canceled)
 17. A method for removing a component attached to aPCB from said PCB, comprising: contacting said component with a contactplate in thermal communication with a heating element such that a vacuumretention port extending through said contact plate is covered by saidcomponent, wherein the contact plate comprises a platform extending fromsaid contact plate that has a substantially identical profile as saidcomponent, and wherein no other portion of said PCB or component iscontacted by said contact plate other than said platform; melting solderattaching said component to said PCB in response to said contacting;creating a vacuum at said vacuum retention port such that said componentis held against said contact plate by said vacuum; and moving saidcontact plate with respect to said PCB during said creating such thatsaid component is retained on said contact plate and removed from saidPCB.
 18. The method of claim 17, wherein said component is anelectro-magnetic shield.
 19. The method of claim 18, wherein saidelectro-magnetic shield is a radio-frequency (RF) shield.
 20. (canceled)21. The method of claim 20, further comprising: selecting a contactplate from a plurality of different contact plates.
 22. The method ofclaim 19, further comprising: removably attaching said contact plate tosaid heating element.
 23. The method of claim 22, wherein said removablyattaching includes clamping said contact plate to said heating elementusing a quick release mechanism. 24.-26. (canceled)
 27. A method forremoving a component from a printed circuit board (PCB), the methodcomprising: moving a removal unit with respect to the PCB having thecomponent attached thereto, the removal unit including a contact platein thermal communication with a heating element, the contact platehaving a platform extending from the contact plate and having asubstantially identical profile as the component; contacting theplatform to the component, wherein during the contacting, no portion ofthe removal unit extends beyond said platform in a direction toward saidPCB to which said component is attached; heating said component by wayof direct conductive heat transfer between said platform and saidcomponent; melting solder attaching said component to said PCB inresponse to said heating; creating a vacuum at a vacuum retention portextending through said contact plate, wherein an inlet of said vacuumretention port is covered by said component during said contacting;repositioning said removal unit with respect to said PCB during saidcreating operation, wherein said component is retained by way of vacuumduring said repositioning to remove said component from said PCB. 28.The method of claim 27, wherein said component is an electro-magneticshield.
 29. The method of claim 28, wherein said electro-magnetic shieldis a radio-frequency (RF) shield.
 30. The method of claim 27, whereinsaid moving operation and said repositioning operation are performed byan actuator.
 31. A method for removing various components from a PCB,the method comprising: first securing a first contact plate to a removalunit, the first securing operation including establishing thermalcommunication between the first contact plate and a heating element andconnecting a first vacuum retention port extending through the firstcontact plate to a vacuum port in the heating element in communicationwith a vacuum source; removing a first component at a first locationfrom the PCB, the removing comprising: contacting the first componentwith the first contact plate such that the component covers the firstvacuum retention port extending through the first contact plate, heatingthe component so as to melt solder attaching the first component to thePCB, and moving the first contact plate with respect to the PCB whilethe vacuum source creates a vacuum at the first vacuum retention portsuch that the first component is retained against the first contactplate and removed from the PCB; second securing a second contact plateto the removal unit, the second securing including establishing thermalcommunication between the second contact plate and a heating element andconnecting a second vacuum retention port extending through the secondcontact plate to the vacuum port in the heating element; and removing asecond component at a second location from the PCB, the removingcomprising: contacting the second component with the second contactplate such that the second component covers the second vacuum retentionport extending through the second contact plate, heating the secondcomponent so as to melt solder attaching the second component to thePCB, and moving the second contact plate with respect to the PCB whilethe vacuum source creates a vacuum at the second vacuum retention portsuch that the second component is retained against the second contactplate and removed from the PCB; wherein the first contact plate includesa first profile substantially identical to the profile of the firstcomponent and the second contact plate includes a second profilesubstantially identical to the second component.
 32. The method of claim31, wherein the first vacuum retention port is offset from the vacuumport when the first contact plate is secured to the removal unit, andwherein the second vacuum retention port is offset from the vacuum portwhen the second contact plate is secured to the removal unit.
 33. Themethod of claim 32, wherein the first vacuum retention port is offsetfrom the vacuum port by a distance corresponding to the first locationand the second vacuum retention port is offset from the vacuum port by adistance corresponding to the second location.
 34. The method accordingto claim 33, wherein the first location is different than the secondlocation.
 35. The method according to claim 34, wherein a first channeldefined in the first contact plate establishes fluid communicationbetween the vacuum port and the first vacuum retention port when thefirst contact plate is secured to the removal unit.
 36. The methodaccording to claim 35, wherein a second channel defined in the secondcontact plate establishes fluid communication between the vacuum portand the second vacuum retention port when the second contact plate issecured to the removal unit.
 37. The method according to claim 31,wherein during the removing operations, no portion of the removal unitextends beyond the first or second contact plate in a direction towardsaid PCB.